【摘要】 针对动磁式直线振荡电机中所用钕铁硼材料失磁的问题,对钕铁硼材料在高温和交变磁场环境中的防失磁设计进行了研究。修正了以往永磁体设计的最佳工作点准则;利用磁路法推导了永磁体在工作温度下的最大去磁工作点的数学表达式,定性地分析了电机的结构参数对最大去磁工作点的影响;利用常温下永磁材料的磁性能推导了工作温度下的拐点位置,给出了高温下直线振荡电机中的钕铁硼材料失磁的判定公式,为直线振荡电机的结构优化设计提供了一个必要的约束条件;对40 M和40 UH两种牌号的钕铁硼材料进行了失磁实验。研究结果表明:实验结果与理论计算结果相一致,该方法可用于钕铁硼永磁材料的选择和直线振荡电机的防失磁设计。更多还原

【Abstract】 Aiming at the problem of irreversible demagnetization of Nd-Fe-B permanent magnet material used in moving-magnet type linear oscillatory actuator,the design of preventing irreversible demagnetization of Nd-Fe-B permanent magnet,which is under the condition of high temperature and alternating magnetic field was studied. The permanent magnet’s traditional design criteria of optimum working point was corrected. The mathematical expression of maximal demagnetizing working point at working temperature was deduced by means of equivalent magnetic circuit method,and the influences of actuator’s structural parameters on maximal demagnetizing working point were qualitatively analyzed. The position of knee point at working temperature was deduced from the magnetic parameters at normal temperature,and the discriminant formula of excitation loss was given,which is a necessary security constraint related to the structural optimization of linear oscillation actuator. Two grade of Nd-Fe-B permanent magnet-40 M and 40 UH-were tested by experiment of excitation loss. The results indicate that the experimental results agree with the theoretical calculation,and this method can be used for the selection of Nd-Fe-B permanent magnet and preventing irreversible demagnetization of linear oscillatory actuator.更多还原